Study On The Attenuation Law And The Determination Of The Difficulty In The Flow Rate Of The Bottom Flow Energy Dissipator

In recent years, with the prosperity development of China’s socialist market economy, as well as tremendous progress in science and technology, China’s water conservancy and hydropower construction to get rapid development. At the same time, people’s environmental awareness is also increasing, the security is also increasing emphasis on the ecological environment, people are no longer just the huge economic benefits as the sole evaluation criteria hydropower projects, but considering the water conservancy and hydropower projects on ecological environment affected. Based on this, the impact of water conservancy and hydropower construction on the ecological environment has become one of the feasibility of the construction constraints.Currently, many of our construction to be built in the medium-sized hydropower projects have the characteristics of high head, large single-wide traffic, while traditional energy dissipator can not guarantee the safety of flood discharge energy dissipation. On this basis, we propose a new type of energy dissipator applied to high head, large single-wide traffic engineering-Lip bottom-flow dissipation. Bottom Lip energy dissipator is in the stilling basin at the entrance of the Stilling formation fell down excavation bucket, constitute a certain vertical depth of Lip stilling basin on the longitudinal section. Due to the presence of Lip, after stilling pond water into the body, forming a submerged jet, swirl and turbulence intensity were cut down energy dissipation in the mainstream, while the high-speed away from the mainstream Stilling, reducing the stilling basin Pro bottom velocity and time are moving hydraulic pressure indicators such as water, can effectively solve the traditional end of energy dissipator bring temporary stilling basin bottom velocity and dynamic pressure when both powerful impact protection floor difficult problem. Lip Energy Dissipation tools have high energy dissipation efficiency, steady state flow into the pool, Atomized small advantages, it can effectively expand the scope of application engineering underflow energy dissipater.This article is based on the National Natural Science Foundation of China, 《The study on hydraulic characteristics of flow structure of falling-sill bottom-flow energy dissipation》 (project number:51169008) standing problem, a pilot study of hydraulic model, combining theoretical analysis, Lip Energy Dissipation hydraulic characteristics of different work flow structure were studied. The main results and conclusions are as follows:(1) Based on hydraulic model test results, study the fall sill height, into the pool of energy, the impact of the Angle to Lip bottom energy dissipator largest temporary bottom velocity, described qualitatively different flow structure of Lip bottom-flow dissipation maximum distribution of temporary bottom velocity; studied Lip height, into the pool of energy, into the pool angle sill bottom-flow energy dissipater plate maximum fall are moving affect water pressure, qualitatively describe Lip bottom energy dissipator different maximum flow structure were moving floor water pressure distribution.(2) Based on hydraulic model test results, study the bottom Lip energy dissipator submerged jet region are mainstream maximum axial velocity decay law, the application of turbulent jet theory, the use of data fitting method to obtain the maximum axial mainstream submerged jet zone linear relationship between the mean velocity decay law and angles into the pool, the pool is deduced angle control target Lip energy dissipator end zone mainstream submerged jet maximum axial velocity decay are semi-empirical formula.(3) Based on hydraulic model test results, study the bottom Lip energy dissipator incident mainstream impact zone axis maximum velocity decay law. Using data fitting method to obtain the incident impact area along the main axis of the velocity distribution curve decay law; hydrodynamic pressure distribution were studied Lip energy dissipator bottom floor impact zone, the deduced impact zone are moving floor water control Hom minimum pressure drop is calculated depth.